Portable alarm apparatus



Nov. 22, 1955 E. F. TOEPFER 2,724,824

PORTABLE ALARM APPARATUS Filed Oct. 20, 1952 INVENTOR.

an; o Ewe ATTORNEY United States Patent PORTABLE ALARM APPARATUS Edwin F. Toepfer, Milwaukee, Wis. Application October 20, 1952, Serial No. 315,715

1 Claim. (Cl. 340-276) The invention relates to burglar and fire alarms.

The main object of the invention is to provide a compact portable burglar and fire alarm apparatus which may be used in a dwelling to protect the same against fire and theft and which also may be used in a portable container containing valuables to sound an alarm if an attempt is made to move it.

The invention further consists in the several features hereinafter set forth and more particularly defined by the claim at the conclusion hereof.

In the drawings:

Fig. l is a vertical midsectional view of alarm apparatus embodying the invention;

Fig. 2 is an enlarged elevation view of one of the parts, parts being broken away and parts being shown in section;

Fig. 3 is a detailed view of parts shown in Fig. 1 with the connector plug inserted therein;

Fig. 4 is an elevation view of a container having the alarm apparatus disposed therein, parts of the container being broken away;

Fig. 5 is a circuit diagram of the alarm arrangement shown in Fig. 4;

Fig. 6 is a view of the alarm apparatus as mounted in a room or building.

Referring to Figs. 1 to 3 of the drawing, the alarm apparatus includes a cylindrical housing formed by a tube 7 of molded or laminated fiber board or other suitable light weight material provided with sheet metal end caps 8 and 9. The cap 8 has a detachable threaded connection with one end of the tube 7 while the cap 9 has a crimped connection with the other end of the tube.

Short spacer tubes 10 of material similar to the tube 7 fit within the end portions of said tube and hold an electric dry battery 11 in position.

The cap 8 is provided with louvres 12 providing openings 13 and with an eye member 14. An electric bell 15 or other suitable electrically operated alarm signalling device has its base anchored to the inner side of the cap 8 by spacer rings 16 and screws 17.

A mercury tilt switch 18, comprising a glass housing 19 containing a pool of mercury 20 and cooperative contacts 21 and 22 is suitably supported in the housing and is shown as secured to the base 23 of a thermal alarm switch 24.

The alarm switch 24 is of known construction and air-chamber 32. A spring member 33 is mounted in the hood 31, one of its ends 34 being firmly secured thereto while its other end 35 is secured in tensioned engagement with the hood by fusible temperature responsive solder 36 adapted to melt at 165 Fahrenheit or more so that 2,724,824 Patented Nov. 22, 1955 the medial portion 33a of the spring will snap down against the diaphragm 30 and flex it sufliciently to move the contact 26 into contact with the fixed contact 25. Also heating of the air in the air chamber 32 by the heating of the hood 31 will produce a pressure in said chamber sufficient to fiex the diaphragm to close the contacts 26 and 25 though gradual rise in temperature will not produce this effect because of a small air vent 37 in the base 23.

A metal bail 38 is mounted on the base 23 to facilitate hanging the device from an overhead support, such as the ceiling 39 indicated in Fig. 6.

The tilt switch 18, and the thermal switch 24 are con nected in parallel with the battery 11 as shown by the upper part of the circuit diagram in Fig. 5. One terminal of the bell 15 is connected by a conductor 40 to one terminal of the battery 11. The other terminal of the battery 11 is connected by branch conductors 41 and 42 to the contact 21 and post 29 of the switches 18 and 24. The circuit is completed through conductors 43, 44 and 45. The conductor 45 may have a normally closed switch 46 including flexible contacts 47 and 48 which may cooperate with the telephone type switch jack or plug 49 shown in Fig. 3 that is adapted to be plugged in through the tube 50 mounted in the tube 7. Closing of the switch 18 or the switch 24 will obviously put the battery 11 in circuit with the bell 15 to sound an alarm.

One way of installing the alarm for use is shown in Fig. 6 wherein the casing is suspended from the ceiling of a room which is to be protected against fire and theft and which may, for example, be a room in a trailer vehicle or a home. A flexible trap cord 51 loosely connects the base of the casing through the eye member 14 with an eyed fastener 52 on an outwardly opening door 53. Another trap cord 54 extends loosely from the member 14 to a connection with the frame 55 of a window 56. The lower sash 57 of the window is connected by a flexible cord 58 to an intermediate portion of the cord 54. If now the door 53 is opened, the cord 51 will swing or tilt the alarm apparatus about its upper suspension, or if the sash 57 is raised, the cords 54 and 58 will similarly act to tilt the alarm apparatus. Tilting of the apparatus closes the mercury switch 18 since the mercury 20 then makes contact with the ring-shaped end 59 of the contact 21, and this closes the circuit to the bell 15 and sounds an alarm so that the occupants of the room will be alerted to an unauthorized entry. Also if a fire starts in the room raising the temperature of the air therein to an extent sufficient to actuate the thermal switch 24, the bell circuit will be closed to sound an alarm.

On many occasions salesmen have to leave valuables in a traveling case in a hotel room, and jewelry salesmen especially may carry their merchandise in a case whose theft represents a considerable loss. In Figs. 3 to 5 I have shown how the alarm apparatus of Fig. 1 may be mounted in a traveling case 60. The housing of the apparatus is shown as secured by retainer member 61 to the side of the case 60, and when the case is left in an upright position, any attempt to move the suitcase will result in the closing of the tilt switch 18 to operate the audible alarm.

To permit the owner to shut off the alarm mechanism at will, the switch jack 49 is plugged in, and this connects the separated terminals 61 and 62 of the jack with the contacts 47 and 48. A conductor 63 connects the terminal 61 with one side of a key-operated switch 64 Whose other side is connected by a conductor 65 with the terminal 62. Thus the switch 64 is connected through contacts 47 and 48 in series with the switch 18. The key controlled lock 66 is mounted in a wall of the case and may be of any suitable construction in which the insertion of a key permits the rotation of a shaft 67 that carries a. cam 68 that acts to open the normally closed switch 64. Thus the owner by inserting the key in the lock 65 and turning the cam 68 may open the switch 64 which is then in series with the switch 18 and thus open the circuit through the conductor 45 so that the closing of the tilt switch 18 is ineffective to operate the alarm.

From the above it will be noted that a simple and compact alarm apparatus has been provided which may be used as a theft and fire alarm either at a permanent location or in a portable container.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claim.

What I claim as my invention is:

A burglar alarm apparatus comprising a housing provided at one end with a bail for suspending the same from a support and provided at its other end with a member References Cited in the file of this patent UNITED STATES PATENTS 1,176,809 Barton Mar. 28, 1916 1,191,783 Harsh July 18, 1916 1,720,230 Murray July 9, 1929 1,814,255 Loeding July 14, 1931 1,965,946 Pincus et a1 July 10, 1934 2,014,474 Hopkins Sept. 17, 1939 2,041,577 Sutherland May 19, 1936 2,202,188 Cianchi May 28, 1940 

